At Cave Point you will find one of the few rocky shorelines that can still be seen along the eastern shores of the Door Peninsula today. This rocky shoreline was formed during the Silurian period, which occurred approximately 440 to 410 million years ago. During this time in geologic history, Wisconsin was located near the Earth’s equator.
As the earth's climate stabilized, large glacial formations went through a process of melt off and retreat. As a result of this melt off, a substantial rise in water levels occurred worldwide. A shallow, warm salt-water sea developed and covered the central portion of North America. This warming gave to ideal conditions for marine life to thrive and develop. Brachiopods, trilobites, crinoids, conodonts, corals, stromatoporoids and many other creatures inhabited this vast inland sea as time went on. This sea bottom, composed of Maquoketa Shale, was then covered with the skeletal remains (Calcium Carbonate) of these ancient marine creatures and sediment from erosion of the virtually lifeless landmasses. This sediment, under pressure, heat and time, transformed into limestone and can be found in various sites throughout the world. In time, calcium particles, within this sediment, were replaced by magnesium, forming yet another even harder sedimentary strata called Dolomitic limestone. These Dolomitic limestone deposits reached heights of more than 800 feet in places, and are now the rock formations that you see throughout the Door Peninsula.
Cave Point Park:
Located next to the 865-acre Whitefish Dunes State Park, this 19-acre county parks main attraction is its limestone sea caves. Take a short walk on the lakeside trail, heading to the North, to view another aspect of the rock formations. The park features a tranquil half-mile long hiking trail where a wide variety of birds and animals can be watched and enjoyed in their natural habitat. A park sticker is "not" required for a visit to Cave Point, but with a visit to Whitefish Dunes State Park nearby, a park sticker "is" required. Caution must be used at this location because of possible slip, trip and fall hazards. During the Winter months, ice cover from the frozen spray of the turbulent Lake Michigan blankets everything, creating a surrealistic world of ice sculptures. Please do not climb the cliffs and remain on the park trails.
Email your answers to the questions below, using the link in my profile only. If your answers are not recieved by me, your log will be deleted. Do not post your answers in your log or I will be forced to delete your entry, according to earthcache rules.
The answers to the questions are found on the information board.
1. State the most obvious cause of erosion of these Limestone rocks at Cave Point today.
2. State the less visible, but possibly more significant, process of erosion of these same rocks. I am looking for the technical terminology for this erosion. (signage)
3. Estimate the height of the cliffs above water level at the highest point surrounding the cave.
Photos are appreciated and accepted, being careful not to show the height of the cave or the information board.
Earthcache Placement Permit #08-27-08 has been submitted to Door County Parks Director George Pinney.